PREVALENCE AND SIGNIFICANCE OF NONSUSTAINED VENTRICULAR-TACHYCARDIA IN PATIENTS WITH PREMATURE VENTRICULAR CONTRACTIONS AND HEART-FAILURE TREATED WITH VASODILATOR THERAPY

Objectives. This study sought to determine the prevalence and signific ance of nonsustained ventricular tachycardia (NSVT) in patients with p remature ventricular contractions (PVCs) and heart failure treated wit h vasodilator therapy. Background. Heart failure patients with ventric ular arrhythmia and NSVT have a significantly increased risk of premat ure cardiac death. Recently there has been the question of whether the se arrhythmias are expressions of a severely compromised, ventricle or are they independent risk factors. We, therefore, determined the prev alence and significance of NSVT in patients with PVCs and heart failur e and on vasodilator therapy, Methods. Twenty-four hour ambulatory rec ordings were done at randomization, at 2 weeks, at months 1, 3, 6, 9 a nd 12 and then every 6 months in 674 patients with heart failure and o n vasodilator therapy. The median period of follow-up was 45 months (r ange 0 to 54). Results. Nonsustained ventricular tachycardia was prese nt in 80% of all patients. Patients without (group 1) and with (group 2) NSVT were balanced for variables: age, etiology of heart disease, N ew York Heart Association (NYHA) functional class, use of amiodarone a nd diuretics and left ventricular diameter by echocardiogram. However, group 1 patients had significantly less beta-adrenergic blocking agen t use and higher ejection fraction (EF) (p < 0.002 and p < 0.001, resp ectively). Survival analysis for all deaths showed a greater risk of d eath among group 2 patients (p = 0.01). Similarly, sudden death was in creased in group 2 patients (p = 0.02, risk ratio 1.8). After adjustin g for the above variables, only EF (p = 0.001) and NYHA class (p = 0.0 1) were shown to be independent predictors of survival. Nonsustained v entricular tachycardia showed a trend (p = 0.07) as an independent pre dictor for all-cause mortality but not for sudden death. Only EF was a n independent predictor for sudden death. Conclusions. Nonsustained ve ntricular tachycardia is frequently seen in patients with heart failur e and may be associated with worsened survival by univariate analysis. However, after adjusting other variables, especially for EE, NSVT was not an independent predictor of all cause mortality or sudden death. These results have serious implications in that suppression of these a rrhythmias may not improve survival. (C) 1998 by the American College of Cardiology.